Motor control system



May 31, 1938. J. H. zAEcKEL 2,119,065

MOTOR CONTROL SYSTEM Filed Aug. 8, 1935 4 Sheets-Sheet l May 31, 1938. J. H. zAEcKl-:L

MOTOR CONTROL SYSTEM Filed Aug. 8, 1935 4 Sheets-Sheet 2 May 31, 1938.

J. H. zAEcfEL 2,119,065

MOTOR CONTROL SYS TEM Filed Aug. 8, 1955 4 Sheets-Sheet 3 May 31, 1938. J. H. zAEcKEL MOTOR CONTROL SYSTEM Filed Aug. 8, 1935 4 Sheets-Sheet 4 Patented May 31, 193s 2,119,065

UNITED sTATEs PATENT oFFieE MOTOR CONTROL SYSTEM Johann Heinrich Zaeckel, Lubeck, Germany Application August 8, 1935, Serial No. 35,369 In Germany August 10, 1934 12 Claims. (Cl. 268-33) This invention relates to an arrangement for free end of which is pivotally connected with a opening and closing garage doors not only by closing arm I0, whereas its lower end is securely hand but also from a motor car by switching on held in a bar II the free end of which is pivotally an .electric motor. The arrangement is charconnected with a closing arm l2. The free end of acterized in that for actuating the electric motor closing arm I2 is shiftably and pivotally conthe Current of the dynamo or battery of the car netted with an arm I3 on the door part B, whereis utilized, which current is conducted through as the closing arm I0 is hingedly connected in a electric contacts arranged on the front of the similar manner with the other door part B. The car and through contact bars arranged directly door parts A A have pins I4 which are each slidon the surface of the ground. able in a guide I5 to enable the door wings A l0 The arrangement need not be connected to an and B to fold to the right and left during the electric supply main but the current is taken opening operation. from the dynamo or battery of the car. To bring A double pawl is oscillatably mounted at the the car contacts to bear against the contact side of the toothed wheel 4 on a shaft I6 jourbars no particular care or accuracy is required, nailed in the bracket I and acted upon by a 15 in any case not more than is necessary for runspring I1, the part I8 of this pawl oscillating ning the car into the garage. When the car is above the toothed wheel 4 (Figs. 4, 5, 6, '7) and standing in the proper position in front of the its part |81 oscillating below this toothed wheel door, for entering the garage, the correct con- 4 (Figs. 3, 4). The toothed wheel 4 has below its netting takes place. teeth e teethlese edge 41 (Fig. 4) with two ep- 20 An embodiment of the invention is illustrated posite notches I9, |91 in which a pin 20 mounted by way of example in the accompanying drawin the Dart |81 engages alternately during the ings in whichzopening and closing of the doors and thus acts Fig. 1 shows in elevation the arrangement for like a latch. The double paWl I8, |131 iS SWllrlg Out opening and closing the door located above these 0f itS looking pOSitOn 0n the 011e hand by the 25 doors. n motor 5, for which purpose two collars 2 I, 2|1 are Fig. 2 is a top plan view of Fig. l. provided on the motor shaft 6, which collars con- Figs. 3 to 7 show details of the arrangement trol a bar 23 rotatable about a pin 22 and 00non an enlarged scale. nected with a spring loaded slide 24 influencing 30 Figs. 8 and 9 show the arrangement for cpenthe pawls I8, |81, and on the other hand by a ing the door by hand, spring loaded crank 29, arranged laterally of Fig. 10 is a diagrammatic view of the electric the dO0r and adapted tO be actuated alSO from installation in the oar, the other side of the door by a crank 291. A rod Fig. 11 is e. similar View of the installation in 28 extends from the Crook 29. which can be 35 the garage. locked by a lock 84, to a swivel 21 rotatably con- Fig, 12 Shows two forms of Construction of nected with a rod 26 the other end of which is switch boardshingedly mounted on a lever plate 25. This plate 1n the Construction `shown in the drawings 25 which is oscillatable about a pin 30 is acted the garage is closed by a double door opening to upon by a Spring 3| and. pTOVded With a Din 32 40 the right and left and consisting of two wings Whieh engages a DFOJeCtlOIl |32 mOunted On the each composed of two hingedly connected parts DaWl |8- The plate 25 has tWO abutment faCeS A and B. Abracket I is arranged above the mid- 33 and 34 which, during the oscillation of the dle of the door, on which bracket toothed wheels plate 25 111 011e Of Other dTeCtOO, OOntaCt With 2, 3y and 4 are rotatably mounted, this bracket catches 35 or 36, so that the toothed wheel 4 is 45 also carrying an electric motor 5 constructed as IOtated thOltgh a Small POYtOIl 0f a leVOllltOn a starter motor. A bevel wheel 1 meshing with in Order t0 mOVe the bars 9, |U and |2 Out of the toothed wheel 2 is mounted on the free end or into their dead centre position. This is necesof a shaft G slidable in the direction of the longisary when it 1S desired tO Open the dOOYS by hand tudinal axis, A pinion 21 connected with the WthOut actuating the gears 2, 3, 4- 50 toothed wheel 2 meshes with the toothed wheel 3 The slide 24 is situated below the toothed wheel and a pinion 31 connected with the toothed wheel 4 and Carries a pin 37 engaging With a Cateh 33 3 meshes with the toothed wheel 4 keyed on a situated below the wheel 4 so that, during the shaft 8 journalled in the bracket I. The upper rotation of the wheel 4, the slide 24 is caused to end of this shaft 8 is tightly held in a bar 9 the oscillate and to liberate the pawl I8, |81 which 55 then swings back under the action of the spring l1 into its locking position for the wheel 4.

A switching device is arranged in the car C (Fig. l). This device consists of a hand lever 39 acted upon by a spring 4Q and provided with an abutment 4i. When the hand lever 39 is thrown over, the abutment 4l presses an armature 42 against a magnet thereby connecting a wire a from a battery 44 with two contacts 45, 46. An air pump 4l regulates the speed of the return movement of the hand lever 39. A wire b leads from the contact 45 over the magnet 43 to a contact 4iarranged on the hand lever 58 and a wire c extends from the contact 45 to a contact 49 also arranged on the hand lever 39; both ci the contacts 45 and slide on a segment-shaped carrier U made of insulating material and carrying two contact strips 5i, 52 for the sliding contact 43 and two other contact strips 53, 54 for the sliding contact 49, the contact 54 being constructed like a comb. The contact strip 5! is conductively connected with the contact strip 54 and the contact strip 52 with the Contact strip Contact bars 55, 55, 5i are arranged directly above the ground in front of the garage door, and on the front of the car sliding contacts 58, 5S, iii@ are suspended, which are connected by wires d, e with the contacts 53, 54 and by a Wire f with the battery 44, over a switch board 6l which, as shown in Fig. l2, can have diierent connections which must correspond with the connections of a switch board 52.

Three wires lead from the contacts 55, 55, 5l to the switching arrangement in the garage. This switching arrangement comprises a switch magn net with armature 54 which connects the two contacts and by wires o, it extending over the switch board 52 either with two contacts S5, 67 or with two contacts 55, 5B. The switching arrangement also comprises a lifting spindle 59. which is raised intermittently by a spring loaded armature 'iii provided with a rotatably mounted falling pawl 'i4 as soon as current impulses are sent into a lifting magnet ii, a spring loaded pawl 12 which in the position shown in dot-dash lines prevents the raised spindle from descending, and a switch. magnet 73 the armature '131 of which correspondingly influences the pawl l2.

The lifting spindle (i5 can also be constructed as a rotary spindle or as a wheel segment provided with teeth.

The current coming from the motor and the diierent magnets returns to the battery 44 through a return lead i. This return lead i exm tends. to a contact 'i5 arranged on the pawl ES, 51 which contact is connected with a contact 'i1 when the pawl is in its position of rest, and with the contact 'i8 when the pawl is lifted out of its notch. The contact l1 is also connected with a contact 'i9 arranged on the lever 23 and which, when the motor shaft ii is retracted, bears against a contact 85 likewise connected up in the lead i. When the shaft 5 is pushed forward the lead i is interrupted at this point.

In the return lead i terminates a lead g2 leading from the contact @i3 over a contact 3i and the motor 5, a lead h1 leading from the contact 55 to the armature 751 and from the contact 'i5 to the lifting magnet li, a lead f7.2 extending from the contact 55 over the switch magnet 53 and a lead g1 extending from the contact tl over the switch magnet The two contacts 3i, till are mounted on an exchangeable element 82 and electrically connected by means of a plate 83 mounted on the lifting spindle 59.

This arrangement operates in the following manner:-

To enable the door to be opened by hand, it must be possible to unlock by lifting the pawl i8, E81 out of engagement with the toothed Wheel 4 and to turn the closing arms 9, i!) and Il, l2 out of their dead centre position in which they hold the door in closed position (Fig. 2). Both these operations are eiiected by turning the crank 29 or 291 causing the lever plate 25 to swing through the intermediary of the rod system 28, 2l and 2S so that the pin 32 lifts the pawl I8, |81 out of its locking position. At the same time the face S3 oi lthe lever plate 25 butts against the catch 35 of the toothed wheel 4 causing this wheel to rotate through a part revolution. The doorwings A, B, A, B can now be pressed apart to the right and left, the pins i4 sliding in the guides l5 (Fig. 2).

When the crank 29 is released it will be returned into its initial position under the action of its spring, thereby also swinging back the lever plate 25. The pawl i8, 31 thus liberated likewise returns into its inoperative position, the pin 2 however cannot drop back into the notch I9 because the toothed wheel 4 has performed a part revolution. The pawl therefore rests n the edge 41 and drops into the notch |91 during the opening of the door and the consequent rotation of the wheel 4. The notch 191 is so arranged that, when the door is open, the closing arms 9, iii and it, i2 are not quite in their dead centre position but shortly in front thereof, and moreover the notch is so shaped that it oiTcrs no resistance to the backward turning of the door, so that the door can easily be closed by hand. When the door ls closed by hand, it is possible that owing to careless closing the door is not locked as the wheel 4 has not been rotated suiiciently far to move the closing arms 9, l@ and il, I2 into their dead centre position and allow the pin 25.] of the pawl i8 to fall into the notch i9. In this instance the lever plate can be caused to swing by a movement of the crank 29 or 291 in the op posite direction, so that the face 34 strikes against the catch 56 thereby rotating the wheel 4 until the locking operation has been completed (Fig. 7).

The manipulation by the cranks 29, 291 for opening the door can be prevented by the lock 84 (Fig. 8).

When opening the doors from the car the following operation takes placez- The circuit arrangement for supplying the current is so arranged that the door can be opened only by a car having a circuit arrangement corresponding with that of the doors.

When the car is being run up to the door its contacts 58, 59, 6@ bear against the contact bars 55, 55, 5'! insulated on the ground (Fig. ll). Ii the lever i9 is swung over against the action of the spring 40, its abutment 4i presses the arma ture 42 against the main closing magnet 43, thereby securely holding the armature 42, and at the same time the two contacts 45, 45 are connected with the battery 44. A lead extends from each of these contacts to the switching apparatus in the interior of the garage. A lead b leads from the contact 45 rst over the main closing magnet 43. The magnet closing circuit is therefore battery a, lc, contact magnet 43, b, 48, 52, 55 d, 6|, 56, 55 g, 62 g1, 13, g1, z', battery, contact 45, c, 49, 54, Gi, 59, 5e, h, G2, h, S5, h1, 15,711, il, h1, z' battery. IThis magnet therefore receives current only when its armature 42 is in contact and is thus securely held. However, as soon as the circuit in which the magnet 43 is connected up is interrupted so that the magnet becomes currentless it releases its armature 42, and the circuit remains interrupted at the two contacts 45, 46 until the armature is again pressed by hand against the magnet 43. Through the connection of the two contacts 45, 46 the current from the battery 44 passes in the leads g, h to the switch arrangement on the door. Each of these leads can be connected within the switching device of the door to two different leads, either to the leads g1 and h1 or to the leads g2 and h2. Which of these leads is actually connected up depends upon the position of the armature 64. There are consequently two main control switch circuits, one being a, c, d, 55, g, armature of main switch whence two wires g1 and g2 extend, the wire g1 leading to the magnet 13 of the locking switch and thence to the common return lead i, and the wire g2 leading to the motor 5 and thence to the common return lead i. The other circlnt is c, e, 56, h, to armature of main switch whence two wires h1 and h2 extend, the wire h1 passing to the armature 131 of the locking switch, contact 15 to magnet 1I of lifting switch and thence to the common return lead i, whereas the other wire h2 extends from the armature 64 to the main switch magnet and thence to the common return lead i.

During the operation of the switching device there are two diiferent periods: First the time during which the spindle 69 is raised and secondly the time during which the motor is running. During the lifting of the spindle the leads g1, h1 must conduct current and whilst the motor is running the leads g2, h2 must conduct current. The lifting magnet 1 I, which periodically receives current, and the motor 5 receive their current directly from the battery 44. No resistance is series connected. The two switching magnets 13 and 63, which have only to hold their armatures 131 and 64 respectively for effecting the control, receive the current which passes over the magnet 43 in the car. This is therefore always connected in series with one of the two magnets 63 and 13.

When the lever 39 in the car is released by the armature 42 after it nas been thrown over and switched in the current the lever returns into its initial position under the .action of the spring 49 being braked by the dash pot 41, and effects various contact connections. First the main closing magnet 43 is connected in the circuit g as long as the contact 48 connected therewith by the wire b is in contact with the contact strip 52. The lead g is connected by the armature 64 being in its position of rest with the Contact 61, from which the lead g1 extends and leads to the switching magnet 13. As the magnet 13 is now under current, it attracts its armature 131 which consequently no longer presses against the arm 121 of the pawl 12 which it has securely held up to this instant, so that the pawl 12 moves towards the lifting spindle 69 and drops into a notch therein.

At the same time the armature 64 connects the lead h` with the contact 65, from which the lead h1 extends in which the lifting magnet 1I is situated. Owing to the fact that the switching magnet 13 has attracted its armature 131, this armature has closed the lead h1 at the contact 15. As soon as the contact 49 directly connected with the battery 44 in the car over the contact 46 comes into Contact with a prong of the contact 54 during the swinging back of the lever 39, the lifting magnet 1I receives current and attracts its armature 10 and, as the pawl 14 of this armature engages in a step of the lifting spindle 69 it lifts this spindle one step. At its last stroke the plate 83 of this i'pindle 69 bears against the under side of the armature 64 and lifts the same so that the connection of the leads y and h through the contacts 65, 61 is interrupted and a connection is established between the lead g and the lead g2 which leads to the motor, and a connection is established between the lead h and the lead h2 in which the magnet 83 is connected up.

Whilst in the car the Contact 49 is in contact with the contact 541, the contact 48 bears not only against the contact 52 but at the same time against the contact strip 5| which is connected with the contact strip 54. The main closing magnet at this moment is connected up not only in the lead g but at the same time also in the lead h, so that this lead h receives current both over the contact 49 directly from the battery 44 and also over the main closing magnet 43 and the contact 48. The lead g1 with the magnet 13 and the lead h1 with the lifting magnet 1I are switched out and currentless, the latter also being currentless owing to the fact that the mag net 13 has released its armature 131 which has thus interrupted the lead h1 at contact 15. At the same time the armature 131 again presses against the arm 121 and thus pulls the pawl 12 away from the spindle 69 so that this spindle drops back into its initial position.

In this position the contact 8l, 811 closes and switches the motor 5 into the lead g2. In the car the Contact 49, as the lever 39 continues its return movement, no longer bears against the contact 541 and the contact 48 is now only connected with the contact strip 5I connected with the contact 541. The main closing magnet is now situated in the lead h, h2 and series connected with the magnet 63. It is therefore displaced from the lead g into the lead h, whereas at thev same time the leads g1 and h1 have been replaced by the leads g1 and h2. As soon as the contact 49 in the car is connected with the contact strip 53, this being the case when the lever 39 has returned into its initial position, the lead g, U2 to the motor is also closed and the motor receives current directly from the batry 44.

As soon as the motor receives current, its shaft 6 moves forward so that the toothed wheel 1 comes into mesh with the toothed wheel 2 which is connected with the toothed wheel 4 by the toothed wheels 2a, 3, 31. During the forward movement of the shaft 6 the lever 23 will turn about its pin 231 so that the slide 34 hingedly connected therewith will be moved in the opposite direction. The slide, before the toothed wheels 1 and 2 come into engagement, strikes against the pawl I8, I81 and lifts the same out of its looking position so that the wheel 4 can rotate freely and the doors can be opened through the intermediary of the arms 9, I9 and II, I2.

When the motor 5 is at a standstill and the shaft 6 pulled back, and when the pawl i8 is in its locking position, the lead z' is closed over the contacts 16, 11, 19, 89. When the pawl I8 is raised out of its locking position and the motor is running, the lead i is closed over the contacts 16 and 18.

At the same time the contact 19 is moved away from the contact 89 and the lead interrupted at this point by the moving forward of the shaft 6 and on the resultant swinging of the lever 23.

As soon as the pawl I8, |81 drops into a notch I9 or |91, its contact 16 connects the lead z' with the contact 19 over the contact 11. As, however, the circuit is interrupted at the contact 79, the motor 5 becomes currentless and stops. The switch magnet in the car also becomes currentless so that it releases its armature and the lead remains continually interrupted at this point. The opening or closing operation Vof the doors is then terminated and all the parte are in their initial positions.

It is not necessary for the contact connections to be established by exactly the mechanical arrangements illustrated in the drawings and above described. These are only given by way of example. The essential feature of the invention is that the diierent contact connections are effected on the one hand by a control lever in the car and on the other hand by the lifting spindle.

The number of prongs on the contact strip .Ei-i and the height of the element B2 carrying the contacts Si, Sil must always be mutually proportioned. If for example the element 82 is too high in relation to the number of contact teeth, the plate 83 ci the spindle @il will already abut against the armature @e before the contact 3S in the car has reached the Contact 5121. The main magnet 43 is then still in the lead g. By raising the armature i4 this lead will then be interrupted, because it has engaged over the contact (i8 the lead U2, which, however, is interrupted at the contact 8i, Sil because the spindle is not in its position of rest. The current flowing over the main magnet 43 is thus interrupted and the armature 42 dropped so that the current is continu ually interrupted. On the other hand, ii the element 82 is too low relatively to the number of con tact prongs, the plate of the spindle ii@ will not yet have reached the armature 54 when the contact 49 in the car, has disengaged from the contact 54l and the Contact @.3 no longer bears against the Contact 52 but bears against the contact 5l. 7L, which receives current over the contacts 48, 5| and 541. As the armature 6d is not raised the leads g1 and h1 are still connected up. As the contact 49 has not yet reached the Contact strip 53, the lead y receives no current, so that the magnet I3 becomes currentless and allows its armature 131 to drop. Thus, the lead 7L is interrupted so that the main closing magnet 45S connected up therein, becomes currentless and releases its armature 42.

The current for the motor 5 is therefore only switched on. when the number of contact prongs 54 corresponds with the height of this element 82. For this purpose the part 5G in the car and the part 82 are exchangeable.

I claim:-

1. A motor control system for opening and c1osing garage doors selectively by hand and by the car battery, comprising in combination an electric motor, a stationary circuit connected to the motor, means in the stationary circuit for controlling its connection to the motor, a circuit on a car, a battery in the car circuit, means on the car for connecting its circuit to the stationary circuit, a switching lever on the car, a holding magnet in the car circuit, an armature for the magnet adapted to make and break the magnets own circuit, and to be forced against the magnet and to energize'the magnet under the action oi the switching lever, a toothed wheel rotatable by said motor, a rod system operatively connected to said wheel and to the garage doors and driven by said wheel to open and shut the garage doors, a locking mechanism adapted to lock said wheel, means for disengaging said mechanism by hand,

The main closing magnet is in the leada mechanical means for disengaging said mecha-- nism by said motor, and means operatively connected to the locking mechanism for die-energizing the holding magnet upon re--engagement oi the locking mechanism and the wheel.

2. In a system as specified in claim l the locking mechanism comprising a. toothless rim on. the toothed wheel, having notches in its periphery, a pawl oscillatable at the side of said rim, a pin carried by said pawl and projecting across said rim, a spring connected to said pawl and adapted to oscillate the same to bring said pin into engagement with one of said notches to lock said wheel, the mechanical disengaging means comprising a second oscillatable pawl arranged adjacent said rst mentioned pawl, a two armed lever connected at one end to said pawl, a pin on the other end of said lever, a shaft projecting from said motor and adapted to be axially shifted at the starting up of the motor, two collars on s said shaft one on each side of said last mentioned pin and adapted to rock said lever during the axial displacement oi said shaft and oscillate said rst mentioned pawl through the intermediary oi" said second pawl to lift said pin out of engagement with the notch in said rim and release said gear wheel, and the means for disengaging said locking mechanism by hand comprising a rod system connected at one end to said pawl, ay

hand crank connected to the other end of said rod system and adapted to actuate said rod system, to oscillate said rst mentioned pawl through the intermediary of said second pawl to lift said pin out of engagement with the notches in said rim.

3. In a system as specified in claim l, a contact rail arranged in front of the garage door, an open circuit connecting said rail with said motor, the control device on the car comprising wide contact plates resiliently mounted on the front of the car and adapted t0 contact with said rail when the car is standing in front of the garage door, a circuit in said car connecting the motor battery with said contact plates and adapted to supplement said open circuit, a main magnet in said car circuit, and an armature of said magnet adapted to be depressed by hand to close said car circuit and said open circuit and connect said battery with the motor.

4. In a system as specified in claim l, a contact rail arranged in i'ront of the garage door, an open circuit connecting rail with said motor. thc control device on the car comprising wide contact plates resiliently mounted on the iront oi the car and adapted to contact with said rail when the car is standing in iront of the garage door, a circuit in said car connecting the motor battery with said contact plates and adapted to supplement said open circuit, a main magnet in said car circuit, and an armature of said magnet adapted to be depressed by hand tc close said car circuit and said open circuit and connect said lbattery with the motor, the car circuit having two branches between thc battery said magnet, one branch leading directly tc the inotor and the other indirectly to the motor over said magnet, a relay being arranged between said magnet and said motor, a common return wire for both of said branches of said car circuit, two break contacts connected in parallel in said re turn wire, one of said contacts held in breaking position by the motor shaft in extended position, and the other contact being maintained in breaking position when its pin is in engagement with a notch in the rim on the toothed wheel when the motor is running and its shaft is in extended position and at the same time the pawl engages in a notch, but is closed when either of these is not the case to temporarily interrupt the circuit to cause the magnet to release the armature and break the circuit and stop the motor.

5. In a system as specified in claim 1 the control device in the garage comprising a circuit connected with the motor, a spindle with a plurality of steps, a lifting magnet adapted to be energized by said circuit, an armature of said magnet adapted to engage the steps of said spindle and lift said spindle one step each time said lifting magnet is energized, and a main switch relay comprising a magnet, and an armature adapted to be pressed against said relay magnet by said spindle.

6. In a system as specified in claim 1 the control device in the garage comprising a circuit connected with the motor, a spindle with a plurality of steps, a lifting magnet adapted to be energized by said circuit, an armature of said magnet adapted to engage the steps of said spindle and lift said spindle one step each time said lifting magnet is energized, and a main switch relay comprising a magnet, and an armature adapted to be pressed against said relay magnet "by said spindle, a spring loaded pawl adapted to lengage in the steps of said spindle to maintain the same in its raised position, a control relay connected with said magnet adapted to close the circuit to said lifting magnet, and an armature of said control relay adapted to rock said pawl out of engagement with said spindle when said control relay is currentless.

'1. In a system as specified in claim 1, the control devices comprising a circuit between the battery in the car and the motor in the garage, a main circuit making magnet in said circuit in said car, said circuit comprising two lead wires leading from said magnet and a common return wire to said battery, a lifting magnet in one of said lead wires, the other of said lead wires extending directly to said motor, a main control relay in said circuit, an armature of said main control relay adapted when said relay is currentless to connect the lead extending directly to said motor with the lead wire leading to said lifting magnet and the lead wire coming from the main circuit making magnet with the control relay of the lifting magnet but when the armature is atitracted, to connect the lead wire coming directly from the battery with said motor and the lead wire coming from the main circuit closing magnet in the car with the magnet of said main control relay.

8. In an arrangement as specified in claim 1, the control device on the car comprising a circuit, a main circuit making magnet in said circuit, an armature of said magnet adapted to close said circuit, a hand operated switch lever adapted to press said armature against said magnet, and a spring adapted to return said lever into its initial position.

9. In a system as specified in claim l the control devices comprising a circuit having two lead wires and a common return wire, a lifting magnet in the garage connected up in` one of said lead wires and adapted to close said circuit, a series of contacts in these lead wires, a hand operated switch lever in said circuit adapted to close said circuit to energize said lifting magnet, a spring adapted. to return said lever into its initial position and said lever adapted to open and close said contacts during its return movement to impart impulses` to said lifting magnet.

10. In a system as specified in claim 1 the control devices comprising a circuit having two lead wires and a common return wire, a lifting magnet in the garage connected up in one of said lead wires and adapted to close said circuit, a series of contacts in these lead wires, a hand operated switch lever in said circuit adapted to close said circuit to energize said lifting magnet, a spring adapted to return said lever into its initial position and said lever adapted to open and close said contacts during its return movement to impart impulses to said stroke magnet, a stroke spindle having a number of steps corresponding with the number of contacts, a pawl adapted to be attracted by said magnet at each impulse to raise said spindle one step, and a main control relay comprising a magnet and an armature adapted to be pressed against its magnet to close the circuit to said motor.

11. In a system as specified in claim l a circuit leading from the battery to the motor, comprising two lead Wires and a common return wire, a main circuit closing magnet in said circuit, a main control relay in the garage connected up in one of said lead wires, a lifting magnet control relay in one of said lead wires adapted to actuate said main control relay, an armature of said lifting magnet connected in its position of rest with said stroke magnet control relay, a contact in said car, a series of contacts connected in the circuit with said step contact, a hand operated lever adapted to press said armature against said main control relay magnet, a spring adapted to return said lever into its initial position, said lever adapted to brush against said series of contacts during its return movement, and impart impulses to said step relay, and said armature adapted to maintain said contact in the car in closed position during the return movement of said lever.

12. In a system as specified in claim 1 a circuit leading from the battery to the motor, comprising two lead wires and a commion return wire, a main circuit closing magnet in` said circuit, a main control relay in the garage connected up in one of said lead wires, a lifting magnet con,- trol relay in one of said lead Wires adapted to actuate said main control relay, an armature of said main control relay connected in its position of rest with said lifting magnet control relay, a Contact in said car, a series` of contacts connected in the circuit with said step contact, a hand operated lever adapted to press said armature against said main control relay magnet, a spring adapted to return said lever into its initial position, said lever adapted to brush against said series of con,- tacts during its return movement, and impart impulses to said step relay, and said armature adapted to maintain said contact in the car in closed position during the return movement of said lever, two additional contacts in the car adapted to be closed by the return movement of said lever, one of said contacts adapted to connect according to the position of the lifting magnet the battery with the main control relay in the garage or with the motor respectively, and the other contact adapted to connect the main circuit closing magnet with the wire connected by the main control relay in the garage either with the control relay of the lifting magnet or with the magnet of the main control relay.

JOHANN HEINRICH ZAECKEL. 

